Present magnetic separators on the market today include radial and longitudinal north and south poles upon each roll between which particulates containing prime material and ferrous particles are passed for the purpose of separating the ferrous particles from the prime material. The use of magnetic separator rolls containing north and south poles do not effectively separate the ferrous particles from the prime material. Strong magnetic forces magnetize the ferrous material particulates north and south so that as the particulates fall from the first roll to the second roll, the respective rolls will repel a certain amount of the oppositely charged ferrous particles and allow them to pass through the flow path since like poles repel. The south pole upon one roll attracts some of the ferrous materials that have been magnetized north. The north pole upon the other roll attracts some of the materials magnetized south.
By providing rolls in a magnetic separator, each of opposite polarity, as the mixture of particulates containing prime material and ferrous particles engage the uppermost roll the ferrous materials are all magnetized north for example and the lower roll all south or negative. As the particulates drop, the ferrous particles therein will be attracted to the lower roll and removed from the flow path of the prime material.
Heretofore particulates containing prime materials and ferrous particles are already run over other magnetic rolls such as in grinding and regrinding processes. Accordingly, the ferrous particles may be either positively or negatively magnetized. Accordingly, when the particulates descend upon the upper magnetic roll some of the ferrous particles will be attracted and some will be repelled. Similarly, as the remaining particulates drop past the second magnetized roll again, some of the ferrous particulates will be repelled and some will be attracted.